Strategies to Prevent AMD Urgently Needed

Age-related macular degeneration (AMD) is a major cause of irreversible vision loss among people of Western European ancestry. It’s estimated that 3.35 million Europeans and 1.75 million Americans are living with sight-threatening AMD. Over the next 20 years these numbers are expected to increase by 50% if preventive interventions aren’t identified. Finding low cost ways to prevent progression to advanced AMD is particularly important since treatments for wet AMD are limited in scope, invasive, costly and may result in complications as severe as end-stage disease.

National Eye Institute researchers have examined whether omega-3 intake is associated with a reduced likelihood of developing central geographic atrophy and neovascular AMD in a cohort within AREDS – a multicenter clinical trial, which ran from 1992 to 2005. The investigators report that participants with the highest omega-3 intake were 30% less likely than their peers to develop dry or wet AMD.

Study Design

The research team looked at a sub-group of 1,837 AREDS participants considered to be at moderate-to-high risk of advanced AMD. Baseline data of omega-3 intake was obtained using a validated food-frequency questionnaire. Trained fundus graders ascertained AMD status from annual stereoscopic color photos by using standardized methods at a single reading center across a 12-year period.

Results

Nearly 20% of participants progressed to dry AMD, and about 32% progressed to wet AMD over the 12-year period. Those in the highest quintile of combined EPA and DHA intake were 30% less likely to develop dry and wet AMD than their peers in the lowest intake quintile. Median intake in the highest quintile was 11% of total calories, based on 2000 kcal daily.

Comments

“If these results are generalizable, they may guide the development of low-cost and easily implemented preventive interventions for progression to advanced AMD”, according to the researchers led by John Paul SanGiovanni. A 4000-person, 5-year randomized clinical trial designed to test the efficacy of omega-3 for this purpose is now underway (www.areds2.org). The omega-3 fatty acids may work by multiple mechanisms. For example, AMD appears to have an inflammatory etiology, and the omega-3s have the capacity to affect pathologic inflammatory processes in the retina.

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